The proposed investigations address the question, "What is a mentally healthy person?" and contrast the predictions of two theoretical traditions: the positive illusions tradition, which proposes that mildly positive self-enhancing illusions foster mental health, social functioning, and protective biological responses to stress, versus the viewpoint that self-enhancement reflects an enduring personality profile marked by self-deceptive neuroticism, a negative impact on social relationships, and greater autonomic responses to stress. We hypothesize that the adaptiveness of self-enhancement depends on whether it is private or manifest in public accountable circumstances; on mode of self-enhancement (direct or indirect); and on sociocultural norms. The main study enrolls 160 participants, approximately half of whom are Asian-American and half of whom are of European-American origin and includes: assessments of mental and physical health; an interview about functioning in life domains related to mental health; and sympathetic (SNS), hypothalamic-pituitary adrenocortical (HPA) axis, and cytokine responses to a series of laboratory stress challenges. The data set also includes peer evaluations and evaluations by friends on each participant. A follow-up component on the main study will provide assessments of the longer-term impact of self-enhancement on psychological functioning, perceptions by others, and health. Questionnaires and protocol analyses of the interviews will enable tests of hypotheses concerning direct versus indirect self-enhancement and the interplay of coping with biological responses to stress. A second study manipulates direct and indirect self-affirmation and examines the impact on psychological and biological stress responses. Given the cultural diversity of the sample, the proposed analyses examine cultural differences in predictors and parameters of mental health and their relation to biological and health measures as well. The overall goal of the research is to provide an integrative understanding of how mental health, social relations, and biological responses to stress are interrelated and whether those interrelations extend across cultures. [unreadable] [unreadable]